In a shallow dish, combine the garlic, oil and the marinade. Place the steak in the dish and turn to coat both sides of the meat. Spoon a few tablespoons of the marinade on top of the steak, cover the dish with plastic wrap, and refrigerate.

Marinate the steak for at least 6 hours, turning the meat over once. Prepare medium-hot grill. Grill the steak for 7-8 minutes on each side for medium rare. Remove the flank steak from grill and let rest for 5 minutes before serving.